package pratice;

import java.util.Collections;
import java.util.Hashtable;
import java.util.Map;

public class CollectionsDemo {
   public static void main(String[] s) {
      //object hash table 
      Hashtable<String,String> table = new Hashtable<String,String>();
      
      // populate the table
      table.put("key1", "value1");
      table.put("key2", "value2");
      table.put("key3", "value3");
      
      System.out.println("Initial collection: "+table);
      
      // create unmodifiable map
      Map m = Collections.unmodifiableMap(table);

      // try to modify the collection
      m.put("key4", "value6");
   }
}